1. Field of the Invention
The present invention relates to a method for concurrent fermentation of a basic amino acid and an acidic amino acid, which comprises culturing a basic L-amino acid-producing bacteria under conditions for producing an acidic L-amino acid or mix-culturing a basic L-amino acid-producing bacteria and acidic L-amino acid-producing bacteria.
2. Discussion of the Background
Simultaneous production of a basic L-amino acid and an acidic L-amino acid by fermentation is unknown heretofore. It has only been known to accumulate any one of a basic L-amino acid and an acidic L-amino acid in a medium. In this case, when two or more amino acids were recognized in a medium, amino acids other than the desired one were present in such a trace amount (several tens of mg/dl) as by-products.
In other words, a method for simultaneously producing a basic L-amino acid and an acidic L-amino acid in a commercially acceptable accumulation amount by fermentation is as yet unknown, though such a method is expected to be advantageous.
Advantages achieved by concurrent production of a basic L-amino acid and an acidic L-amino acid by fermentation involve possible reduction of the amounts of ionic components in a medium, which results in the prevention of an increase of osmosis during incubation thereby improving fermentation productivity (improve the rate of forming amino acids), reduction and saving of medium components, simplified treatment of fermentation broth (operation for isolating amino acids), reduction in the amount of waste liquid after isolating and obtaining amino acids from the fermentation broth, etc. In particular, reduction in the amount of waste liquid is an advantage which cannot be overlooked at this point of time when keen attention is being currently paid to environmental preservation.